How to create a task in Windows Task Scheduler

Introduction

A brief example of how to create a simple task in Windows Task Scheduler using VB. NET

Background

Tested on Windows 8.

A question in the CodeProject Quick Answers area prompted me to create a test program that shows how to create a task in Task Scheduler.

Specifically, the behavior of the Hidden attribute was in question. I used this code to determine the cause of the issue. See the comments in the code below to learn about the issue with the Hidden attribute.

Using the code

Copy the source code and modify to your needs. If you need C#, use one of the free code translators to translate it for you.

Add a Reference to C:\WINDOWS\SYSTEM32\taskschd.dll or C:\WINDOWS\SYSWOW64\taskschd.dll which will create Interop.TaskScheduler.dll.

Imports TaskScheduler

Public Sub CreateSchedule()
    Dim taskService As ITaskService = New TaskScheduler.TaskScheduler()

    ' Connect to the TaskService
    taskService.Connect()

    ' Create a new task definition and assign properties
    Dim taskDefinition As ITaskDefinition = taskService.NewTask(0)
    taskDefinition.Settings.MultipleInstances = _TASK_INSTANCES_POLICY.TASK_INSTANCES_IGNORE_NEW
    taskDefinition.RegistrationInfo.Description = "Testing the creation of a scheduled task via VB .NET"
    taskDefinition.Principal.LogonType = _TASK_LOGON_TYPE.TASK_LOGON_GROUP
    taskDefinition.Settings.Hidden = False ' Set to True when running task should be hidden
    ' NOTE: When Hidden is true, it does not work if _TASK_LOGON_TYPE.TASK_LOGON_INTERACTIVE_TOKEN 
    '       is used as parameter to RegisterTaskDefinition
    '
    '
    ' Add a trigger that will fire the task every other day
    Dim taskTrigger As IDailyTrigger = _
        DirectCast(taskDefinition.Triggers.Create _
            (_TASK_TRIGGER_TYPE2.TASK_TRIGGER_DAILY), IDailyTrigger)
    ' Set to start ten minutes from now
    taskTrigger.StartBoundary = _
        DateTime.Now.AddMinutes(10).ToString _
        ("yyyy-MM-ddThh:mm:ss" & _
        TimeZone.CurrentTimeZone.GetUtcOffset(Now).ToString.Substring(0, 6))
    ' Rerun the task every other day
    taskTrigger.DaysInterval = 2


    ' Create the Task action 
    Dim taskAction As IExecAction = _
        DirectCast(taskDefinition.Actions.Create(_TASK_ACTION_TYPE.TASK_ACTION_EXEC), IExecAction)
    ' The Path to the program
    taskAction.Path = "C:\windows\notepad.exe"
    ' Set Arguments
    taskAction.Arguments = ""
    taskAction.WorkingDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)


    ' Register the task in the Task Scheduler's root folder
    Const taskName As String = "Testing creation of a scheduled task"
    Dim rootFolder As ITaskFolder = taskService.GetFolder("\")
    rootFolder.RegisterTaskDefinition( _
       taskName, taskDefinition, _
       CInt(_TASK_CREATION.TASK_CREATE_OR_UPDATE), _
       "MyUsername", "MyPassword", _
       _TASK_LOGON_TYPE.TASK_LOGON_INTERACTIVE_TOKEN_OR_PASSWORD)

    ' Clean up the COM variables
    While System.Runtime.InteropServices.Marshal.ReleaseComObject(rootFolder) <> 0
        Application.DoEvents()
    End While
    rootFolder = Nothing
    While System.Runtime.InteropServices.Marshal.ReleaseComObject(taskTrigger) <> 0
        Application.DoEvents()
    End While
    taskTrigger = Nothing
    While System.Runtime.InteropServices.Marshal.ReleaseComObject(taskAction) <> 0
        Application.DoEvents()
    End While
    taskAction = Nothing
    While System.Runtime.InteropServices.Marshal.ReleaseComObject(taskDefinition) <> 0
        Application.DoEvents()
    End While
    taskDefinition = Nothing
    While System.Runtime.InteropServices.Marshal.ReleaseComObject(taskService) <> 0
        Application.DoEvents()
    End While
    taskService = Nothing
    GC.Collect() ' Start .NET CLR Garbage Collection
    GC.WaitForPendingFinalizers() ' Wait for Garbage Collection to finish
End Sub

History

• Version 1 - 14 June 2013.